Composition of matter



ill

bill

Patented Sept. 27, 1932 UNITED STATES PATENT OFFICE 'WILLSON H. ROWIJEY, OF CHARLESTON, WEST VIRGINIA, ASSIGNOR TO EVANS LEAD COMPANY, OF CHARLESTON,

WEST VIRGINIA, A CORPORATION OF DELAWARE COMPOSITION OF MATTER No Drawing. Original application filed November 7, 1930, Serial No. 494,194. Divided and this application filed December 10, 1981.

In storage batteries, particularly automo' bile starting and lighting batteries, much depends upon the negative plates for best capacities. In such batteries there is a tendency of the sponge lead composing the active material of the negative plate to contract, coagulate and weld together the lead part1- cles. As this contraction,coagulation and welding together is more noticeable in cold weather, the capacity of the plates is greatly reduced and sometimes the battery is thereby rendered worthless.

With these facts in mind the present invention is directed to a new material to be used in the making of negative plates of the pasted variety for storage batteries or storage cells, and has for one of'its objects the provision of a material which not only promotes separation of the lead particles of the plate mass but maintains this particle separation thereby preventing contraction, coagulation and; welding together of the lead particles of the active material in the plate and forming a Well cemented plate of high porosity, capacity and efiiciency.

My new and improved material also reduces abnormal swelling and dislodging of the active material of the plate from its supporting grid. v A further object of my invention is the provision of a material preferably in a dry powdered form which may be employed by manufacturers of storage batteries or storage cells for incorporation by them in the paste. or mix used in making negative plates.

This dry material is'not only non-corrosive, but it is easily mixed with battery oxides to give a uniform paste with a minimum of efi ort. Moreover, by means of this dry material the proportions of the dry material and battery oxides can be more easily adhered to by a workman unskilled in the art of battery making, thereby giving uniform" results inproduction. The dry material also has good keeping qualities, and it can bestored or shipped without deterioration.

More specifically the present invention is directed to a new composition of matter for use in the manufacture of negative plates and stora 'e batteries this new com osition Serial No. 580,222.

of matter resulting from the mixing of a material, such as lead oxide for example, capable' of combining chemically with the acids in the mass which results from treating a fibrous cellulosic carbon-containing material with sulphuric acid.

By Way'of example I may take 14 ounces become partially carbonized but still retaining a fibrous condition.

The treatment of hemp or other suitable fibrous cellulosic material with sulphuric acid, as above set forth, not only produces a partially-carbonized fibrous cellulosic material but also results in unreacted and reactreduction products of the sulphuric. acid, artial decomposition products of oxycellu ose, and also soluble organic salts, such as sulphonates and sul hates of sugars, which latter are capable of orming lead salts on treatment with lead oxides.

The heating'is then discontinued and the resulting mass, preferably when cooled, is mixed with lead oxide in such proportions that all of the liquid of the mass will combine with the oxide. I have found that about 2500 cubic centimeters of the material to 17 pounds of lead oxide (PbO) will be about the right proportions: with the result that the lead oxide not only combines with the unreacted sulphuric acid and the, unreacted reduction products but also with the sulphonates of the organic matter carried in the sulphuric acid toform lead sulphonates and/or organic lead salts such as organic lead sulphates.

The thorough agitation and incorporation of the aforesaid material with the lead oxide in a mixer produces a paste-like mass capable in this condition of being incorporated in a 'ed sulphuric acid and unreacted and reacted may be dried and reduced by a suitable mill" to a powder, and in this condition incorporated in the paste or mix used in making negative plates.

5 I have found that the addition of my improved material to the late mix results in increased sulphation oi the lead oxide and an increase in bulking, the latter feature permitting more plates to be made with a given amount of pigment.

I have found also that the incorporation of this material in the mix apparently effacts not only a permanent separation of the particles in the material of thefinished plate 15 but also an increased particle separation, as

compared with results obtained where lampblack, for example, is used.

' It is to be noted that my improved material is superior to the materials, such as lampblack for example, heretofore used and known commercially as expanders, in that excessive swelling of the plateis eliminated. This is of advantage because it avoids entirely the danger of the plates swelling to such a degree 25 as to contact with the positive plates and thus cause a short circuit in the battery. It also eliminates sloughing of the active mass from the supporting grid. It further eliminates entirely the difiiculty experienced with prior plates when removing the same from the cell and placing them again in position.

While I have referred to lead oxide as a material suitable for carrying out my invention, it is to be understood, however, that other materials such for example as basic lead sulphate or metallic lead powder may be used with good results.

This application is a division of my copendin application Serial No. 494,194, filed N ovember 7, 1930.

What I claim is 1. A dry composition of matter for addition to the negative plate mix for storage butteries and containing a partially-carbonized cellulosic material, lead sulphate and organic lead salts.

2. A composition of matter for addition to the negative plate mix for storage batteries and comprising a dry powder containing. partially-carbonized fibrous cellulosic material,

lead sulphate and organic lead salts.

This specification signed this 2nd day of December, 1931. u WILLSON H. ROWLEY. 

